Signaling system for mines and the like.



. G. T. PLUMB.

SIGNALING SYSTEM FOR mums AND THE LIKE.

APPLICATION FILED MAY 18, 1908. 1,102,951 Patented July 7, 1914.

THE NORRIS PETERS COT. PHOTO'LITHQ, WASHINGTON. D- C.

TTED STATES PATENT OFFICE.

GEORGE THOMAS PLUMB, OF JOHANNESBURG, TRANSVAAL SIGNALING SYSTEM FOR MINES AND THE LIKE.

inoaesi.

Mines and the like, of which the following is a specification.

This inventlon relates to electrical sig naling systems employed in mines and the like.

The existlng open parallel systems possess the important advantages that a signal can be transmitted to the engine driver by any person from any signaling point so that any pre-arranged urgency signal can be immediately transmitted in the case of accidents Or for any other urgent reason; and that all the bells throughout the system are rung when the circuit is closed to transmit a signal from any point. In the locking systems in use however it is only possible for those persons possessing a key giving access to the transmission device to transmit a signal. In the open signaling systems however it will be apparent that any unauthorized person can transmit a signal to the driver in the engine room.

The object of the invention is to enable the engine driver to differentiate between false and true signals or between signals transmitted by unauthorized and authorized persons and so render the signaling system as safe as possible.

Under the existing systems the ringing of a false or unauthorized si nal is usually known only to the skipman (the person in charge of the skip and authorized to transmit the signals) whereas under my improved system the ringing of false or unauthorized signals is known to both the skipman and the driver and is not recognized by the latter, who awaits the true or authorized signal from the skipman. Under these circumstances it is absolutely necessary that the signals from the skipman to the driver shall be transmitted without hindrance.

My improved system also insures that in cases of cross-ringing (the simultaneous transmission of signals from more than one point) it is impossible to interrupt the communication between the skipman and the driver.

As in a signaling system incorporating my present invention the entire system is left Specification of Letters Patent.

Application filed May 18, 1908.

Patented July 7, 1914.

Serial No. 433,541.

open I obtain all the advantages of such open system. i

The employment of my invention not only prevents accidents but a considerable saving of time in hauling is effected by its use.

Theinvention consists essentially in the combination with the ordinary signaling system of an auxiliary wire or earth return, a two-way switch associated with each signal transmitting .device, and an indicator visible or audible or both visible and audible to the engine driver.

A further advantage of the invention is that the indicator is always actuated unless there is a complete disorganization of the system, that is to say so long as there is a suiiiciently powerful current the indicator will be actuated even though the bells or their equivalent are weak or inaudible.

The invention will befurther described by aid of the accompanying drawing, in which I diagrammatically depict it adapted to the ordinary parallel or three-wire system, but it is to be understood that it Dna-y be adapted to any other suitable sys- 1 represents the three wires of the circuit of the ordinary parallel or open bell signaling system and 2 are the batteries or generators of electric energy.

I, The dotted line a:-w represents the collar of the shaft or surface level and the dot-ted line yy the first level. The signaling gear is shown as arranged between the engine room and the first and second levels of a mine, but it will be apparent that it may be extended to any desired number of levels or points, the signal transmitting device associated with the bell or its equivalent being interposed in the circuit at each level or other point at which it is desired to receive and transmit signals.

3 represents the several bells interposed in the electric circuit and 4 the pulls or pushes which constitute the signal transmitting devices. The mode of operating the system to transmit signals to and from the engine room is well known and need not be further described.

5 represents the additional or auxiliary and safety wire. I prefer to use the wire 5 as being the most reliable in use but it is to be understood that an earth return may be substituted therefor.

6 represents any suitable form of two-way mittedthrough the auxiliary wire 5.

"shown in the position in which it is placed through the auxiliary wire 5, and the dotted switch associated with each signal transmitting device. This two-way switch is capable of being actuated only by means of a key or its equivalent which is ordinarily carried by the skipman. The switch 6 associated with the signal transmitting device for the first level is shown in position for the signals to be transmitted through the ordinary system, and its alternative position, represented by thedotted line, is that into which it is placed 'by the skipman to transmit his signal through the auxiliary wire 5. The switch 6. associated with the signal transmitting device for the second level is by the' skipmanto transmit his signals line represents-the position 'in which it is placed for the signals to be transmitted through the ordinary parallel or open system.

7 represents two (more or less) suitable series-wound magnets, or coils in series with the auxiliary wire 5. These magnets 7 serve for actuating the indicator 8. The indicator 8, which is placed in a position in the engine room visible to the engine driver is moved by the coils only when the signals are trans- B this means the movement'of the indicator 8 clearly indicates to the engine driver that the signal is a true or authorized one. In lieu of the indicator shown it will be apparent that any other suitable 'form of indicator may be used, such as a movable shutter, disk, lamp, bell or equivalent. One or moreadditional cells, as indicated at 9, may be added and the auxiliary wire 5 be connected therewith in the manner indicated.

What I claim as my invention and desire to protect by Letters Patent is 1. Incombi-nation, a signal receiving sta tion, a-sigiialtransmitting station, a signal device and a circuit closer at the trans- I initting station, a source of current, a connection from one s1de of sald source to the signal device, a connection from the other cement this atent may be obtained for five cents each, by afldre'ssin'gthe can-inasmuch:

side of said source to the circuit closer, at

common conductor extending from the re-' ceivlng station to the transmitting stat1on,g

tion, a magnetically controlled indicator in theauxiliary conductor at the receiving station, a two-way switch at the transmitting station, said switch in oneposition' being in the connection from the'source of'current to the circuit closer, and in the other'position arranged to open such connectlon and con-- nect the circuit-closerto the auxiliary ductor.

2. In combination, a signal receiving sta-' tion, a plurality of signal transmitting Star tions, a signal bell and a circuit closer. at

con-

each station, a source of current, a connec tion from one side of said source to each bell, a connection Irom the other s1de-of said source to each circuit'closer, a common v conductor extending from the recelving station to the transmitting stations, the other sides of the'bells'and circuit closers at each station being connected'to the common con-- ductor, an" auxiliary conductor extending from the second named side of the'b'attery Witnesses:

CHAS. OVENDALE," R. OVENDALE.

Patents,

Washington, D; '0. 

